Fuel compositions



United States Patent C) 3,305,329 FUEL (IQMPGSHTHGNS Homer J. Sims, Horsham, Pan, and Harry 1?. White, Riverside, Nl, assignors to Rohm & Haas Company, Philadelphia, Pa, a corporation of Delaware No Drawing. Fiied May 29, 1963, Ser. No. 284,024 12 Claims. (Cl. re-63) This invention deals with novel fuel composition having incorporated therein novel specific cyclic amidines. It more particularly deals with liquid hydrocarbon distillate fuel compositions.

The cyclic amidines employed in the compositions of the present invention may be represented by the formula in which R is alkyl of 1 to 24 carbon atoms or phenyl, naphthyl, =benzyl or alkyl substituted phenyl, naphthyl or benzyl in which the total alkyl substituents contain up to 16 carbon atoms, R is hydrogen or alkyl of 1 to 24 carbon atoms, collectively R and R may form a ring with the nitrogen atom to which they are joined, namely morpholino, thiamorpholino, piperidino and pyrrolidinyl, X is ethenylene, ethylene, alkyl or .alkenyl substituted ethylene having a total of up to 20 carbon atoms, a 1,2-cyclohexylene or alkyl substituted 1,2-cyclohexylene having a total of up to 16 carbon atoms, 1,2-cyclohexenylene or alkyl substituted 1,2-cyclohexenylene having a total of up to 16 carbon atoms, 2,3-bicyclo[2.2.1]hept-S-enylene and 2,3-bicyclo[2.2.1]heptylene, R is hydrogen, 2-hydroxyethyl, 2-aminoethyl, 2 or 3-hydroxypropyl, 2 or 3-aminopr-opyl, 2 or 3-(2-aminoethyl)aminopropyl, 2 or 3-(2 or 3-aminopropyl)aminopropyl or 2-('2-aminoethyl)aminoethyl, and D is a divalent saturated chain of 2 to 3 carbon atoms whose available valences are satisfied by hydrogen atoms or alkyl groups having a total of 12 carbon atoms and combinations of hydrogen and alkyl groups having a total of 12 carbon atoms or 1,2-cyclohexylene.

It is necessary that in the cyclic amidine molecule R plus R plus X contain at least 10 carbon atoms, for the purposes of this invention.

Typically R represents methyl, butyl, octyl, dodecyl, octadecyl, tetracosyl, phenyl, naphthyl, benzyl, octylphenyl, butylnaphthyl and octylbenzyl.

Typical individual embodiments of R include hydrogen, methyl, butyl, octyl, dodecyl, octadecyl, eicosyl and tetracosyl.

Typical embodiments of the X include ethylene, ethenylene, dimethylethylene, octylethylene, dodecylethylene, dodecylbutylethylene, dodecenylethylene, cyclohexylene, methylcyclohexenylene, octylcyclohexenylene and 3,6- methano-1,2-cyclohexenylene.

Typical embodiments of the symbol D include ethylene, dimethylethylene, butylethylene, octylethylene, propylene, dimethylpropylene, butylpropylene, octylpropylene and 1,2-cyclohexy1ene.

A particularly effective embodiment of the above cyclic amidines includes either R or R as a tertiary alkyl group, that is, an alkyl group having the configuration in which A represents alkyl groups that total from 3 to 23 carbon atoms, preferably from 11 to 23 carbon atoms. Particularly outstanding results are obtained when this spatial configuration is present in either or both of R or R In all respects with regard to the groups R and R but particularly when the tertiary alkyl structure is contemplated, each of R and R may represent a single alkyl group or mixtures of alkyl groups within the stated carbon content range. Commercially available compounds that provide this part of the molecule are known to contain mixtures of alkyl groups. Particularly outstanding in this respect are those in which either R or R represents a mixture of tertiary alkyl groups containing 12 to 15 carbon atoms averaging 13 carbon atoms or a mixture of 18 to '24 carbon atoms.

Especially outstanding embodiments are those in which R or R represent tertiary alkyl groups of 12 to 24 carbon atoms, X is ethylene or ethenylene, R is hydrogen, 2- hydroxyethyl, or Z-aminoethyl and D represents ethylene.

The cyclic amidines used in the present invention are prepared by reacting a compound having the formula with one having the formula R NHDNH at the reflux temperature of the reaction system. It is possible to conduct the reaction without a solvent or if a solvent is preferred, which is generally the case, one may employ an inert aromatic compound such as benzene, toluene, zylene, or the like. Toluene and Xylene are preferred, particularly with the higher molecular weight reactants. The reaction is conducted at the boiling point of the reaction system and is continued until two moles of water per mole of acid are removed. The water is removed from the reaction mixture as the reaction progresses either by distillation or when a solvent is employed, by an azeotropic distillation. The reagents are employed in equimolecular quantities or, if desired, an excess of the amine may be used. If excess amine is employed in order to assure highest yields, the excess may be removed by distillation such as under reduced pressure or small amounts of excess amine need not be removed since it does not interfere with the functioning and utility of the cyclic amidine product.

Yields of the cyclic amidines employed in the present compositions are consistently in excess of 90% and frequently approach a quantitative result.

Typical embodiments of the amine reactants include ethylenediamine, diethylenetriamine, triethylenetetramine, hydroxyethylethylenediamine, propylenediamine, dipropylenetriamine, tripropylenetetraamine, hydroxyethylpropylenediamine. Typical embodiments of the amidoacid reactants include N-butylmaleamic, N-octylmaleamic, N-dodecylmaleamic, N octadecylmaleamic, N benzylmaleamic, N-p'henylmaleamic, N-naphthylmaleamic, N- butylsuccinamic, N,N -dioctylsuccinamic, N octylsuccinamic, N-dodecylsuccinamic, N-octadecylsuccinamic, N- phenylsuccinamic, N-benzylsuccinamic, N-butyldodecenylsuccinamic, N-octylcumylsuccinamic, N-octyloctenylsuccinamic, N-phenyldodecenylsuccinamic, N-t-dodecyltetrahydrophthalamic, N-lbutyltetrahydrophthalamic, N- octadecyltetrahydrophthalamic, N-dodecyl-3,6 methanotetrahydrophthalam-ic and N octyltetrahydrophthalamic acids.

The cyclic amidines defined hereinbefore, are incorporated into distillate fuels according to usual techniques wherein they supply carburetor anti-icing activity, carburetor detergency, anti-rust activity and sludge dispersancy, when employed in amounts of about 0.001 to 2.0% by weight of the cyclic amidines to the distillate fuel contemplated. The preferred range is about 0.005 to 1.0% by weight.

It is to be understood that the distillate fuels contemplated are those that boil from about 75 to 750 P. which includes gasoline, jet and diesel fuels and furnace oils.

The present compounds are particularly useful in fuels that boil up to about 600 F., that is, the normal gasolines and jet fuels. The need for an additive to supply the above enumerated properties is widely recognized in the art since lack of such activity and combinations thereof in distillate fuels leads to a marked diminution of commercial value of such distillate fuels.

The compositions of the present invention were subjected to a standard carburetor anti-icing test which is a test to evaluate the stalling characteristics of a fuel. The test employed a 1957 Buick engine, equipped with a factory radiator, manifold, carburetor, and an automatic choke. The motor parts are stabilized at 4014 F. The test was conducted at 40:4 F. and 90% humidity. The motor was accelerated to 1500 r.p.m. for one minute and then reduced to idle for seconds. If the engine stalled, such was recorded and the engine was immediately restarted, accelerated to 1500 r.p.m. for one minute and then reduced to idle for 30 seconds. If stalling did not occur during the 30 seconds idle time, the speed of the motor was accelerated to 1500 r.p.m. and the cycle was repeated. This was continued until the engine was com pletely warmed up and the number of stalls was recorded. In this test, the base fuel, resulted in nine stalls. With as little as 0.02% by weight of a defined cyclic amidine of the present invention the number of stalls was reduced at least by 33 /s%. Particularly outstanding in this test is the cyclic amidine of this invention wherein R represents tertiary octadecyl, R is hydrogen, X is ethenylene, D is ethylene and R is 2-aminoethyl.

The present compositions were evaluated in a standard carburetor detergency test in which there was employed a 1954 model 6-cylinder Plymouth engine. The carburetor was equipped with a clear plastic throttle body. The crankcase blowby from the engine was returned to the carburetor air inlet. The engine was operated on a base fuel under cyclic conditions until the throttle body of the carburetor was covered with black deposits. There was then incorporated into the same base fuel one of the specific cyclic amidines of the present invention in order to provide a composition of this invention. The test was then continued for an additional 5 hours. The evaluation was based on the black deposit that remained after clean-up. Commercially available compositions reduce black deposits to 3236%. The compositions of the present invention reduced the black deposits to 34% even when there was employed only 0.02 gram of a cyclic amidine of the present invention per 100 ml. of fuel. Particularly outstanding in this respect was a composition of the present invention containing the cyclic amidine wherein R represents tertiary octadecyl, R is hydrogen, X is ethenylene, D is ethylene and R is 2-aminoethyl.

The compositions of the present invention were subjected to an anti-rust test, ASTM D-665, Procedure A for distilled water, modified to use isooctane at 75 F. for a period of 24 hours. The base fuel itself gave a result of 100% rust. The defined cyclic amidines of the present invention when used in amounts as low as 0.01 gram per 100 ml. of the base fuel gave no rust at all. Particularly outstanding in this test were the compositions of the present invention containing the cyclic amidine in which R is tertiary octadecyl, R is hydrogen, X is ethenylene or ethylene, D is ethylene and R is hydrogen, 2-hydroxyethyl or Z-aminoethyl.

The compositions of the present invention were subjected to a sludge dispersancy test as described by F. L. Nelson, D. P. Osterhout and W. R. Schwindeman, Ind. Eng. Chem. 48, 1892 (1956). The test consists of preparing a liter of fuel oil containing a candidate additive for sludge dispersancy. In the same fuel oil composition there is incorporated four grams of synthetic sludge. The oil is then circulated for one hour through a single stage oil burner pump containing a 100 mesh strainer. The sludge deposit on the strainer is collected and weighed. The fuel oil without any additive led to an accumulation of sludge of 250 mg. The use of commercially acceptable sludge dispersants lead to less than mg. of sludge accumulation. The compositions of the present invention having incorporated therein a defined cyclic amidine in amounts of 0.01 to 0.02 gram per 100 'ml. of fuel oil gave sludge accumulations of less than 40 mg. down to 2 mg. Particularly effective in this test were those compositions containing a specific cyclic amidine wherein R represents a mixture of tertiary alkyl groups, on the one hand, having betweent 12 and 15 carbon atoms, averaging 13 carbon atoms, and, on the other hand, having from 18 to 24 carbon atoms and a neutral equivalent of about 300 to 340. Outstanding results were also obtained when R represented hexadecyl, octadecyl or tertiary butyl. Outstanding embodiments of R were hydrogen, hexadecyl and octadecyl. Particularly effective embodiments of X were ethylene, ethenylene, cyclohexenylene and dodecenylethylene. The most effective embodiments of D were ethylene and 1,3-propylene. Outstanding results were obtained when R represented hydrogen, 2-hydroxyethyl or 2-aminoethyl.

The present invention may be more fully understood from the following examples which are offered by way of illustration and not by way of limitation. Parts by weight are used throughout.

Example 1 A solution of N-t-octadecylmaleamic acid (215 parts) and diethylenetriamine (51.5 parts) in 350 parts of xylene is heated to reflux and the evolved water removed by azeotropic distillation. After 12 hours of refluxing 18 parts of water and 1.5 parts of excess amine are removed. The solvent is then removed under reduced pressure and the product obtained as the residue. The product contains 10.3% nitrogen (theoretical 11.3%) and is identified as the compound of the present invention wherein R is a mixture of tertiary alkyl groups averaging 18 carbon atoms, R is hydrogen, X is ethenylene, D is ethylene and R is Z-aminoethyl.

Similarly a compound employed in the present invention is prepared exactly as above except that R represents hydroxyethyl. The product contains 8.2% nitrogen (theoretical 8.4%) and had a neutral equivalent of 485 (theoretical 498).

Example 2 A solution of N,N-dihexadecylmaleamic acid (269 parts) and diethylenetriamine (55 parts) in 400 parts of xylene is refluxed for 3 hours during which time 18 parts of water is azeotropically removed. The xylene is removed leaving a residue of 307 parts of a product which is identified as the cyclic amidine of this invention in which R, and R are hexadecyl, X is ethenylene, D is ethylene and R is Z-aminoethyl. The product contains 8.6% nitrogen (9.3% theoretical).

Similarly there is prepared a cyclic amidine of this invention wherein R and R are octadecyl, X is ethenylene, D is ethylene, R is Z-aminoethyl and contains 7.1% nitrogen (8.0% theoretical).

Example 3 A solution of N-t-octadecylmaleamic acid (43.6 parts) and ethylenediamine (6.0 parts) in 86 parts of xylene is heated to reflux and the water removed as an azeotropic mixture. After two hours 2.2 parts of aqueous layer has been removed and 3.0 parts of ethylenediamine is added. Refluxing is resumed for three hours after which time a total of 5.0 parts of aqueous layer containing 3.0 parts of water and 2.0 parts of amine has been removed. The xylene is then removed by vacuum distillation leaving 48 parts of product as the residue. The product contains 9.2% nitrogen (9.1% theoretical). The product is a cyclic amidine in which R, is tertiary octadecyl, R is hydrogen, R is hydrogen, D is ethylene and X is ethenylene.

Similarly there is prepared a cyclic amidine of this invention having the same structure as that above except that R represents tertiary octyl.

There are also prepared in a similar manner the cyclic amidines of the present invention in which R represents dodecyl or octadecyl, R is hydrogen, X is ethenylene, D is ethylene and R is hydrogen or Z-arninoethyl.

Example 4 There are mixed together 29.1 parts of N-t-tridecylmaleamic acid (in which the tridecyl represents a mixture oftertiary alkyl groups of 12 to 15 carbon atoms having an average of 13 carbon atoms) and 10.3 parts of diethylenetriamine. The temperature rises to about 80 C. and the mixture is then heated up to 155 C. over a period of 2% hours under a slow stream of nitrogen. Water is distilled oflf and the heating discontinued. The mixture is cooled to about 100 C. and the remainder of water removed. A total of 3.8 parts of distillate is collected containing 0.5 part of amine. The product is recovered as a residue amounting to 35.1 parts and contains 14.2% nitrogen (15.6% theoretical). The product has a neutral equivalent of 208 (179 theoretical). The product is a cyclic amidine in which R is tertiary tridecyl, R is hydrogen, R is Z-aminoethyl, X is ethenylene and D is ethylene.

In a similar way, similar cyclic amidines of the present invention are prepared which have the same structure as above except that when R represents hydrogen the product contains 12.7% nitrogen (13.3% theoretical) and has a neutral equivalent of 298 (315 theoretical) and when R represents 2-hydroxyethyl the product contains 10.6% nitrogen (11.6% theoretical).

Example 5 A mixture of N-t-octadecyltetrahydrophthalamic acid (94.8 parts) and diethylenetriamine (20.6 parts) is refluxed in 367 parts of xylene for five hours. The water evolved is removed by azeotropic distillation. After five hours an additional 2.8 parts of diethylenetriamine is added and refluxing continued for 24 hours. The xylene is removed under reduced pressure and the product is recovered as the residue. The product is a cyclic amidine of this invention in which R represents an alkyl group having a tertiary alkyl structure and containing an average of 18 carbon atoms, R is hydrogen, X is cyclohexenyl, D is ethylene and R is 2-aminoethyl. The product contains 9.0% nitrogen (10.3% theoretical).

Similarly there are prepared the cyclic amidines of this invention wherein R represents a mixture of tertiary alkyl groups of 12 to 15 carbon atoms, averaging 13 carbon atoms, R is hydrogen, X is cyclohexenyl, D is ethylene, and R is hydrogen, Z-hydroxyethyl or 2-aminoethyl. When R is Z-aminoethyl the product contains 12.8% nitrogen (13.5% theoretical). When R is 2- hydroxyethyl the product contains 11.9% nitrogen (11.3% theoretical).

Example 6 A solution of N-t-octadecylsuccinarnic acid (216 parts) and hydroxyethylenediamine (52 parts) in 367 parts of xylene is refluxed. The Water that is formed is removed as an azeotropic mixture over 15 hours. The aqueous layer contains 1.3 parts of amine. The xylene is removed under reduced pressure leaving 260 parts of product as the residue. The product contains 7.6% nitrogen (7.6% theoretical). It has a neutral equivalent of 497 (500 theoretical) In a similar way there is prepared the product of this invention wherein R represents tertiary alkyl groups having an average of 18 carbon atoms, R is hydrogen, X is ethylene, D is ethylene and R is hydrogen. This product contains 8.3% nitrogen (9.1% theoretical).

Similarly a product is prepared as above wherein R represents 2-aminoethyl and contains 9.1% nitrogen (9.2% theoretical).

In like manner there are prepared the cyclic amidines of the present invention wherein R represents a mixture of tertiary alkyl groups containing 12 to 15 carbon atoms, averaging 13 carbon atoms, R is hydrogen, X is ethylene, D is ethylene. When R is Z-aminoethyl the product has a neutral equivalent of 189 (180 theoretical). When R represents 2-(2-aminoethyl)aminoethyl the product contains 15.7% nitrogen (17.3% theoretical). When R is hydrogen the product contains 12.7% nitrogen (13.2% theoretical) and has a neutral equivalent of 298 (315 theoretical) Example 7 A solution of N-t-butyldodecenylsuccinamic acid (67.8 parts) and diethylenetriamine (20.6 parts) in 200 parts of xylene is refluxed for 8 hours during which time the water is removed as an azeotropic mixture. An additional 2.3 parts of diethylenetriamine is introduced and refluxing is continued for an additional five hours. A total of 8.3 parts of aqueous layer is separated. The reaction mixture is stripped leaving the product as a residue of 72 parts. The product has a neutral equivalent of 205 (203 theoretical). The product is the cyclic amidine of this invention wherein R is tertiarybutyl, R is hydrogen, X is dodecenylethylene, D is ethylene, R is 2-aminoethyl.

In like manner a similar product is prepared in which R represents a mixture of tertiary alkyl groups containing from 12 to 15 carbon atoms, averaging 13 carbon atoms, R is hydrogen, X is dodecenylethylene, D is ethylene and R is hydrogen.

Example 8 A solution of N-t-octadecylmaleamic acid (43.0 parts) and N,N'-bis-y-(aminopropyl)ethylenediamine (20 parts) in 200 ml. of xylene is heated at reflux for 2% hours. The water which forms is removed by azeotropic distillation. After 3.8 parts of water has been collected, the solvent is removed leaving a residue of 60.3 parts. The product contains 11.4% nitrogen (11.8% theoretical) and is identified as fi[1-(aminopropylaminoethyl)-1,4,5,6- tetrahydropyrimidin-Z-yl1-N-t-octadecylacrylamide.

A similar compound may be made from N-t-tridecylsuccinamic acid (31.1 parts) and N,N-bis-' -(aminopropy l)ethylenediamine (20 parts).

Example 9 A solution of N-phenyl-a-dodecenylsuccinamic acid (36 parts, 0.1 mole) and diethylenetriarnine (10.3 .parts, 0.1 mole) in xylene parts) is heated at reflux for a total of 21 hours while water is removed azeotropically. A total of 3.7 parts of aqueous layer is collected containing 3.1 parts of water. The xylene solvent is removed under vacuum. This also removes some aniline which is displaced during the reaction. The residue has less than 3% acid as determined by titration with alcoholic potassium hydroxide. The neutralization equivalent of the residue is 223 (theoretical 213). The product is a cyclic amidine in which R is phenyl, R is hydrogen, R is 2-aminoethyl, X is dodecenylethylene and D is ethylene.

A similar product is prepared where R is t-butyl.

Example 10 A mixture of N-t-octylsuccinamic acid (22.9 parts, 0.1 mole) and diethylenetriamine 10.3 parts, 0.1 mole) in parts xylene is heated to reflux for 12 hours. Water is removed azeotropically. The aqueous layer which collected in the Water separator weighs 3.7 parts and contains 3.3 parts of water. The xylene is removed from the reaction mixture by distillation up to about 80 C. at 20 mm. of mercury. The residue (27.4 parts) has a neutralization equivalent of 147 and contains 18.1% nitrogen (theoretical 18.9%). The product is a cyclic amidine in which R is t-octyl, R is hydrogen, R is 2-aminoethyl, X is ethylene and D is ethylene.

7 We claim: 1. A liquid hydrocarbon fuel having incorporated therein in an amount SllfilCiBIli to impart anti-rust activity at least one cyclic amidine having the formula in which R individually is a member of the class consisting of alkyl of 1 to 24 carbon atoms, phenyl, naphthyl, benzyl and alkyl substituted phenyl, naphthyl and benzyl in which the total alkyl substituents contain up to 16 carbon atoms;

R individually is a member of the class consisting of hydrogen and alkyl of 1 to 24 carbon atoms;

R and R collectively form a ring, with the nitrogen atom to which they are joined, from the class consisting of morpholino, thiamorpholino, piperidino and pyrrolidinyl;

R is a member of the class consisting of hydrogen,

Z-hydroxyethyl, Z-aminoethyl, 3-hydroxypropyl, 3- aminopropyl, 2-(2-aminoethyl)aminopropyl, 3-(2- aminopropyl aminopropyl, 2-(2-aminoethyl) aminoethyl and Z-(Z-aminopropyl)aminoethyl;

X is a member of the class consisting of ethylene, ethenylene, alkyl and alkenyl substituted ethylene having a total of up to 20 carbon atoms, 1,2-cyclohexylene, 1,2-cyclohexenylene, alkyl substituted 1,2- cyclohexylene and 1,2-cyclohexenylene having a total of up to 16 carbon atoms, 3,6-methano-l,2-cyclohexylene and 3,6-rnethano-1,2-cyclohexenylene; and

D is a member of the class consisting of 1,2-cyclohexylene and a divalent saturated chain of 2 to 3 carbon atoms whose available valences are satisfied by members of the class consisting of hydrogen and alkyl and combinations thereof in which all of said alkyl has a total of up to 12 carbon atoms in which the number of total carbon atoms in R R and X is at least 10.

2.'A fuel according to claim 1 in which said cyclic amidine is present in amounts by weight of about 0.001 to 2.0%.

3. A fuel according to claim 1 in which said cyclic amidine is present in amounts by weight of about 0.005 to 1.0%.

4. A distillate fuel having incorporated therein about 0.001 to 2.0% by weight of at least one cyclic amidine having the formula having the formula il) N R1NCX-C// D l B2 N in which R represents tertiary alkyl of 12 to 24 carbon atoms; R is hydrogen; R is hydrogen;

8 X is ethenylene and D is ethylene. 6. A distillate fuel having incorporated therein about 0.001 to 2.0% by weight of at least one cyclic amidine having the formula in which R represents tertiary alkyl of 12 to 24 carbon atoms;

R is hydrogen;

R is Z-hydroxyethyl;

X is ethylene and D is ethylene.

7. A distillate fuel having incorporated therein about 0.001 to 2.0% by weight of at least one cyclic amidine having the formula in which R represents tertiary alkyl of 12 to 24 carbon atoms; R is hydrogen; R is 2-aminoethyl; X is ethylene and D is ethylene. 8. The composition of claim 1 wherein R is tertiary alkyl averaging 18 carbon atoms; R is hydrogen; R is Z-aminoethyl; X is ethenylene and D is ethylene. 9. The composition of claim 1 wherein R is hexadecyl; R is hexadecyl; R is 2-aminoethyl; X is ethenylene and D is ethylene. 10. The composition of claim 1 wherein R is tertiary alkyl averaging 18 carbon atoms; R is hydrogen; R is hydrogen; X is ethenylene and D is ethylene. 11. The composition of claim 1 wherein R is tertiary alkyl averaging 13 carbon atoms; R is hydrogen; R is Z-aminoethyl; X is ethenylene and D is ethylene. 12. The composition of claim 1 wherein R is tertiary alkyl averaging 13 carbon atoms; R is hydrogen; R is Z-aminoethyl; X is 1,2-cyclohexenylene and D is ethylene.

References Cited by the Examiner UNITED STATES PATENTS 5/1962 Hamer et al 44-63 5/1963 Andress 44-63 OTHER REFERENCES DANIEL E. WYMAN, Primary Examiner. W. J. SHINE Assistant Examiner. 

1. A LIQUID HYDROCARBON FUEL HAVING INCORPORATED THEREIN IN AN AMOUNT SUFFICIENT TO IMPART ANTI-RUST ACTIVITY AT LEAST ONE CYCLIC AMIDINE HAVING THE FORMULA 